Viewing archive of Thursday, 12 August 2004

Solar activity report

Report of Solar-Geophysical Activity 2004 Aug 12 2200 UTC
Prepared by the NOAA © SWPC and processed by

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 225 Issued at 2200Z on 12 Aug 2004

IA. Analysis of Solar Active Regions and Activity from 11-2100Z to 12-2100Z

Solar activity was moderate. Region 656 (S13W09) produced one M-class flare during the past 24 hours, an M1/1f at 0505UTC. The remainder of the day's activity consisted of occasional C-class flares from Region 656. This region continues to grow and has an area of about 1320 millionths. It also continues to be magnetically complex and is classified as a beta-gamma-delta magnetic configuration. Old Region 652 quietly rotated around the east limb and was assigned as Region 661 (N08E84).
IB. Solar Activity Forecast
Solar activity is expected to be moderate, and Region 656 is expected to dominate activity. There is a chance during the next three days for an isolated major flare event from Region 656.
IIA. Geophysical Activity Summary 11-2100Z to 12-2100Z
The geomagnetic field was quiet to unsettled. Solar wind data shows the continuing presence of a high speed coronal hole stream, but the influence on geomagnetic activity is weakening as the velocity is declining. The greater than 2 MeV electron flux reached high levels during the past 24 hours.
IIB. Geophysical Activity Forecast
The geomagnetic field is expected to be mostly unsettled for tomorrow (13 August). Conditions are expected to increase slightly to unsettled to active on the 2nd day (14 August) with the arrival of a slow CME that was observed late on 10 August. Conditions should return to mostly unsettled for the third day (15 August).
III. Event Probabilities 13 Aug to 15 Aug
Class M 70%70%70%
Class X 20%20%20%
IV. Penticton 10.7 cm Flux
  Observed       12 Aug 147
  Predicted    13 Aug-15 Aug  150/155/165
  90 Day Mean        12 Aug 107
V. Geomagnetic A Indices
  Observed Afr/Ap 11 Aug  010/013
  Estimated     Afr/Ap 12 Aug  010/010
  Predicted     Afr/Ap 13 Aug-15 Aug  010/010-015/012-010/010
VI. Geomagnetic Activity Probabilities 13 Aug to 15 Aug
A. Middle Latitudes
Minor storm 15%15%15%
Major-severe storm 05%05%05%
B. High Latitudes
Minor storm 15%20%15%
Major-severe storm 05%05%05%

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